Fire extinguishing foam apparatus



March 6, 1956 1.. E. MITCHISON 2,737,413

FIRE EXTINGUISHING FOAM APPARATUS Filed Feb. 1951 I 1 (it INVENTOR.

Lows l-HsoN ATTORNEY United States Patent "ice 52711:

FIRE EXTINGUISHING FOAM APPARATUS Louis E. Mitchison, Baltimore, Md., assignor to National Foam System, Inc., West Chester, Pa.

Application February 6, 1951, Serial No. 209,587

3 Claims. (Cl. 299-84) This invention relates generally to apparatus for producing fire-extinguishing foam and more particularly to an improved construction and design of a portable unit which is adapted to be connected to a suitable source of water supply, as by way of an ordinary garden hose, for the production of so-called mechanical or air foam.

Among the principal objects of the present invention is to provide a mechanical foam producer unit which is adapted to be quickly-detachably secured to the conventional container for the foam-forming liquid employed in the production of mechanical. fire-extinguishing foam, the unit with the liquid container secured thereto, being designed to be conveniently held in the hand for application of the foam to the fire to be extinguished.

A further and important object. of the invention is to provide a simple, economical and. efiicient foam producing unit which is designed for use with foam-forming liquidcontainers which are of relatively small. capacity and so inexpensive as to permit of their being discarded when emptied of their contents, the foam-producingv unit. being so adapted for quick-detachable operative connection to the container as to permit of quick and easy replacement by a full container of liquid of one which has become exhausted of its contents, thus insuring a substantially continuous supply of foam-forming liquid for the pro duction of fire-extinguishing foam.

Still another object of the present invention is to provide a self-contained foam-producing unit. which includes as component parts thereof: (1) means for introducing foam-forming liquid from a container to which the unit is quick-detachably secured into a stream of water passing through the unit by the suction of the water stream; (2) means for inducing air into a finely divided stream of the foam-forming. solution to produce the fire-extinguishing foam; and (3) means for insuring the discharge of the foam at requisite velocity and in adequate volume in the form of a stream which may be directed as desired for application to a fire, the unit constructed of the component parts as aforesaid being designed for convenient holding in the hand and including means, readily engaged by the finger of the hand holding the unit, for effecting at will the introduction of the foam-forming liquid into the water stream. Thus, by this last-mentioned means, the unit is instantly adapted to discharge either water or foam against a fire.

More specifically, it is an object of the present invention to provide the foam-producing unit with a vent which, while normally open to atmosphere, is adapted to be closed to atmosphere by the finger of the hand in which the unit is held to thereby subject the liquid in the container to which the unit is secured to the suction pull of the stream of water passing through the unit and so cause it (the liquid) to be introduced into the water stream only so long as the vent is closed to atmosphere. The provision of this atmospheric vent is of considerable advantage not only because it enables the unit to be selectively employed to discharge either water or foam against the fire, but also because it prevents waste of foam during 2. theoperation of replacing, a filled container of foamforming liquid. for one that has been exhausted of liquid. Inasmuch as the foam-forming liquid is drawn into the flowing water stream only while the aforesaid control vent is closed to atmosphere, it will be appreciated that by maintaining it freely open to atmosphere,- the unit may be detached from one container and secured to another Without necessitating shutting off the flow of Water therethrough in order to prevent any undesired or unintended use of the foam-forming liquid. Thus, the latter is drawn from its container only when foam is required to be produced and when the unit is operatively under the full control of the person handling the same.

Other objects and advantages of the present invention will appear more fully hereinafter, it being understood that the present invention consists substantially in the combination, construction, location and: relative arrangement of parts, all as will appear more fully hereinafter, as shown in the accompanying drawings and as finally pointed out in the appended claims.

In the accompanying drawings,

Figure 1 is a side elevational view of the foam-producing unit of the present invention showing the same operatively associated with: acontainer of foam-forming liquid;

Figure 2 is a vertical sectional view of the foam.- producing unit as taken along the line 22 of Figure 4;

Figure 3 is a sectional view of a detail of construction astaken along the line 33 of Figure 2;

Figure 4 is a partial front. elevational view of. the unit as viewed from. the line 4-4 of Figure2;

Figure 5 is-a sectional view of a detail of construction as taken along the line 5-5 of Figure: 1; and

Figure 6 is a top plan view, partially in section, of the assembly as viewed from the line 66 of Figure 2.

Referring now more particularly to the drawings, it will be observed that the foam-producing unit of the present invention designated generally by the reference numeral 10, is adapted for quick-detachable securement to a container 11 such as is conventionally employed for storing and shipping the foam-forming liquid which is introduced into a flowing water stream to form a foam solution which is converted into foam when such solution, while being discharged as a finely divided, high velocity stream, is entrained with air from atmosphere. Such production of fire-extinguishing foam is presently well known in the art, the subdivided stream of the foam solution with the air entrained thereof being generally directed into and through a tube for discharge therefrom in the form. of a foam stream. A satisfactory type of such tube, in which. the foam is formed and which is employed to direct the foam to the fire to be extinguished, is that which is shown and described in United States Letters Patent No. 2,247,998, of August 16, 1949.

The foam producing unit 10 of the present invention includes as component parts thereof a foam discharge tube 12 as well as a liquid discharger head or nozzle member 13 with which the tube 12 is operatively associated and which is adapted to be connected to a conduit 14, such as a flexible garden hose, through which water, under suitable pressure is supplied to the foam-producing unit for mixture therein with the foam-forming liquid supplying thereto from the container 11. The nozzle member or discharger head 13 may be of any suitable construction, preferably such as that shown and described in United States Letters Patent No. 2,512,456, of June 20, 1950.

As is most clearly shown in Figure 2, the noggle member or the discharge'r head 13 and its associated foam discharge tube 12 are fixedly mounted upon a support 15 which is in turn adapted for such. quick-detachable securement to the container as to constitute the latter a component part of a portable assembly, such as is shown in Figure 1, which may be held by the hand to present the foam discharge tube 12 in position for the most efficient and direct application to a fire of the fire-extinguishing foam issuing from the tube. The hand-hold or support 15 is in the form of a vertically extending post of generally oval cross-section, the front edge of which is preferably provided with a series of spaced indentations 16 to respectively receive the fingers of the hand in which the support is held, the support being thereby more positively held against slipping from or in the hand while the unit is in use.

The upper end of the support 15 is provided with a hollow cylindrical part 17 in which is fixedly seated, as by a pressed fit, the discharger head 13 which essentially comprises a cylindrical main body member 18 having a central pa1t 19 which is axially bored and terminates in an outwardly flared discharge end 20. Disposed coaxially within this flared discharge end of the axially bored part 19 is a frusto-conical deflector element 21 which provides conjointly with the discharge end 24) of the part 19 an outwardly flared annular discharge passage for the foam-forming solution, this deflector 21 being preferably externally fluted as described in the aforesaid Letters Patent No. 2,512,456 for the purposes therein stated. The deflector is preferably supported in place by a rod or stem 22 which extends axially through the part 19 and is suitably secured at its rear end to the main body of the discharger head, also as fully described in said patent No. 2,512,456.

The passage through the central part 19 of the discharger head includes a rear section 23 of such restricted diameter in relation to that of its enlarged forward section 24 as to form an ejector for drawing foam-forming liquid from the container 11 into the water stream by the suction induced by the latter as it emerges from the passage 23 and passes through the enlarged passage 24, the foam-forming liquid being drawn into the latter passage by way of an inlet port 25 opening through the side wall of the central, axially bored part 19.

This inlet port 25 is in communication with an enlarged chamber or recess 26 which is formed in the upper end of the support 15 immediately beneath the cylindrical part 17 thereof, this chamber or recess being in turn in free communication with a passage 27 extending vertically through the support, as most clearly appears in Figure 2. The lower extremity of this passage 27 is enlarged, as at 28, and the portion thereof just above such enlargement is internally threaded, as at 29, to threadedly receive a suction tube 30 which is adapted to project into the liquid container 11 when the foam producing unit It is operatively associated with the container. In this connection it will be noted that the suction tube 30 is of a length suflicient to present its lower open end in close proximity to the bottom of the container, the location of the lower end of the suction tube and its spacing from the bottom of the container being normally such as to insure effective withdrawal of the maximum amount of liquid from a given container by the suction action of the water stream flowing through the discharger head 13.

The foam discharge tube 12, which, as indicated above, may be of any suitable design and construction, and which includes adjacent its rear end a plurality of air inlet openings 31 through which air from atmosphere is entrained into the foam solution as it is discharged from the discharger head 13, is preferably threaded, as at 32, into the main body member 18 of the discharger head, the tube 12 being thus secured in axial extension of the discharger head for delivery therethrough and discharge therefrom of the fire-extinguishing foam. Preferably, the cylindrical socket 17 for the discharger head 13 is disposed with its axis inclined with respect to the horizontal to insure an upwardly and forwardly directed throw of the foam stream when the assembly shown in Figure l is held in normal position.

As has been stated hereinbefore, the container 11 for the foam-forming liquid is of the conventional form ordinarily used for storage and shipment of the liquid, its capacity being normally two gallons and its construction being such as to economically permit of its being discarded when emptied of its contents. This conventional type of container is ordinarily provided with a sealed-in top closure 33 having formed therein a pouring neck 34 which is normally closed by a removable closure cap (not shown), the top closure 33 being also provided with a pivoted carrying bail 35 which may be swung into its vertical position best shown in Figures 2 and 4.

The foam producing unit 10 of the present invention is adapted for detachable securement to the top closure 33 of the container with the suction tube 3i) of the unit projecting downwardly into the container ll through the pouring neck 34 thereof. In order to eifect such operative assembly of the unit is with the liquid container, the hand-hold or support 15 of the unit is provided with a circular bottom part 36 which is recessed, as at 3'7, to snugly fit over the circular rim of the pouring neck 34 of the container when the suction tube is projected into the container, as best shown in Figure 2. A sealing gasket 38 is desirably interposed between the pouring neck 34 of the container and the recessed bottom 37 of the support 15 to eifect an air-tight seal therebetween, it being observed that when the parts are so assembled the enlarged recess 28 at the lower end of the suction passage 27 and which surrounds the suction tube Si) is in free communication with the interior of the pouring neck 34 and with the space above the level of the liquid in the container. In order to subject this space to atmospheric pressure and so prevent creation of a vacuum in the container as the liquid is withdrawn therefrom, the recessed bottom part 36 of the hand-hold or support 15 of the foam-producing unit is provided with a transversely extending air inlet passage 39 leading into the enlarged recess 28 surrounding the upper end of the suction tube 30 for introduction of air from atmosphere by way of such recess into the interior of the container.

For quick-detachable securement of the foam-produc ing unit 10 in operative relation to the liquid container 11, the bottom part 36 of the unit is provided with a lateral extension 40 which is adapted to be engaged by the carrying bail 36 when the latter is swung into its vertical position as shown in Figures 2, 4 and 6, the lateral extension 40 being grooved in its upper surface, as at 41, to provide a seat for the bail. Also, it will be noted that the outer end of the lateral extension 40 is provided with an adjustable foot in the form of a bolt 42 threaded into the bottom of the extension, this bolt having a knurled head 43 which rests upon the top closure 33 of the container and by means of which the bolt is axially adjusted relatively to the extension 40 to force the latter into securely locked engagement with the bail 36. To uncouple the foam-producing unit from a given container, it is only necessary to rotate the bolt in direction to shorten its effective length whereupon the bail 36 is freed of its locking engagement with the lateral extension 40 and thereby permit the unit 10 to be detached from its associated container.

It will be observed that the hand-hold or support 15 of the unit it) is provided adjacent its upper end with a lateral passage 44 having its outer end open to atmosphere and its inner end in communication with the chamber or recess 26, which latter in turn is commonly in communication with the liquid inlet port 25 of the discharger head 13 and the suction passage 27 extending vertically through the support 15. This passage 44 is so located as to permit its outer end to be sealed off from atmosphere by a finger (shown dotted in Figure 2) of the hand by which the unit is held, the function of this passage when open to atmosphere being to break the vacuum or suction pull of the water stream flowing through the discharger head upon the foam-forming liquid in the container 11.

It will be apparent that when the passage 44 is closed to atmosphere, as by the finger shown dotted in Figure 2, the stream of Water flowing under high velocity through the discharger head will draw into it by the suction induced in the passage 24 of the discharged head liquid from the container 11 to form a foaming solution which is converted into foam when air is entrained there in by way of the air inlet openings 31 of the foam discharge tube 12. Immediately, however, upon opening the passage 44 to atmosphere, the suction pull upon the foam-forming liquid in the container is interrupted, and, consequently, so long as the passage 44 remains open to atmosphere there will be no production of foam nor any withdrawal of foam-forming liquid from the container, even though water continues to flow through the discharger head 13 and its associated foam discharge tube 12.

The passage 44 thus provides an extremely efficient and easily manipulated means for instantly adapting the apparatus of the present invention for the projection of either water or foam against a fire to be extinguished. Also, this vacuum-breaking passage 44 serves advantageously to prevent waste of the foam-forming liquid, such as might occur while the foam-producing unit with water flowing through it is being detachably coupled to a filled container of the foam-forming liquid, it being apparent that such coupling may be efiected without the necessity of shutting off the supply of water through the unit and without producing foam by the simple expedient of maintaining the passage 44 open to atmosphere.

In order to insure a proper proportioning of foamforming liquid to the water flowing through the discharger head, the suction tube may be provided in its upper end with a metering adapter 45 (see Figure 3) in the form of an apertured disk threaded or otherwise removably secured in position with the suction tube. It will be understood that by providing interchangeable adapters having central openings of different diameter, the proportion of foam-forming liquid to water may be varied as desired.

It will be understood, of course, that the form and construction of the discharger head 13 and of the foam discharge tube 12 may be varied as desired and that still other changes may be made from time to time without departing from the general principles or real spirit of the present invention. Accordingly, it is intended to claim the invention broadly, as well as specifically, as indicated in the appended claims.

What is claimed as new and useful is:

1. In a fire extinguishing foam-producing unit of the character described, in combination, a disposable container adapted to be charged with a foam-forming liquid, said container being provided with a closed top having a. liquid dispensing opening therein, a main body member having an upstanding portion adapted to be held in the hand, a nozzle member supported at the upper end of said body member for creating and discharging a high velocity stream of water with which said liquid may be mixed to form a foam-forming solution, said nozzle including means for the introduction of said liquid into the flowing stream of water by the suction action of said flowing stream, a suction tube depending from said body member, for projection into said container, said suction tube being in communication with a passage extending through said upstanding portion of the nozzle supporting member, a lateral extension at the bottom of said body member adapted to seat against the closed top of the container at a point spaced to one side of the dispensing opening in said container top, and a bail swingably mounted upon said container top and adapted to engage over said lateral extension to lock the said body member operatively in position to seal said dispensing opening with the said suction tube projecting downwardly through said opening.

2. In a fire extinguishing foam-producing unit as defined in claim 1 wherein the swingable bail is adapted to engage over a portion of the lateral extension spaced from the point at which said lateral extension is seated against the closed top of the container.

3. In a fire extinguishing foam-producing unit as defined in claim 1 wherein the swingable bail is adapted to engage over an intermediate portion of the later extension and the lateral extension is provided at its outer end with an adjustable element operable to bear against the top of the container for raising said outer end of the extension and rocking said extension about said bail so as to lower the body member and cause the latter to bear against the top of the container for effectively securing said body member in position for sealing the dispensing opening.

References Cited in the file of this patent UNITED STATES PATENTS 560,922 Pearson May 26, 1896 1,036,871 Matheson Aug. 27, 1912 2,069,352 Brookshire et a1 Feb. 2, 1937 2,543,294 McCabe Feb. 27, 1951 

